资源类型

期刊论文 1525

会议视频 28

会议信息 2

年份

2024 1

2023 61

2022 116

2021 106

2020 77

2019 105

2018 87

2017 89

2016 67

2015 87

2014 82

2013 64

2012 78

2011 75

2010 72

2009 50

2008 71

2007 85

2006 35

2005 24

展开 ︾

关键词

风险分析 9

能源 7

分析 4

可持续发展 4

对策 4

影响因素 4

数值模拟 4

隧道 4

ANSYS 3

农业科学 3

抗击疫情 3

数值分析 3

环境 3

营养健康 3

裂缝 3

2035年 2

BNLAS 2

COVID-19 2

DX桩 2

展开 ︾

检索范围:

排序: 展示方式:

Assessment of temporal and spatial variations in water quality using multivariate statistical methods

Xue LI,Pengjing LI,Dong WANG,Yuqiu WANG

《环境科学与工程前沿(英文)》 2014年 第8卷 第6期   页码 895-904 doi: 10.1007/s11783-014-0736-z

摘要: This study evaluated the temporal and spatial variations of water quality data sets for the Xin'anjiang River through the use of multivariate statistical techniques, including cluster analysis (CA), discriminant analysis (DA), correlation analysis, and principal component analysis (PCA). The water samples, measured by ten parameters, were collected every month for three years (2008–2010) from eight sampling stations located along the river. The hierarchical CA classified the 12 months into three periods (First, Second and Third Period) and the eight sampling sites into three groups (Groups 1, 2 and 3) based on seasonal differences and various pollution levels caused by physicochemical properties and anthropogenic activities. DA identified three significant parameters (temperature, pH and ) to distinguish temporal groups with close to 76% correct assignment. The DA also discovered five parameters (temperature, electricity conductivity, total nitrogen, chemical oxygen demand and total phosphorus) for spatial variation analysis, with 80.56% correct assignment. The non–parametric correlation coefficient (Spearman R) explained the relationship between the water quality parameters and the basin characteristics, and the GIS made the results visual and direct. The PCA identified four PCs for Groups 1 and 2, and three PCs for Group 3. These PCs captured 68.94%, 67.48% and 70.35% of the total variance of Groups 1, 2 and 3, respectively. Although natural pollution affects the Xin'anjiang River, the main sources of pollution included agricultural activities, industrial waste, and domestic wastewater.

关键词: Xin'anjiang River     multivariable statistical analysis     temporal variation     spatial variation     water quality    

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

《环境科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 649-664 doi: 10.1007/s11783-014-0702-9

摘要: Fuzzy comprehensive assessment and multivariate statistical techniques including cluster analysis, discriminant analysis, principal component analysis, and factor analysis were applied to analyze the water quality status of Yuqiao Reservoir Basin, North China, for assessing its spatio-temporal variations and identifying potential pollution sources. In this paper, we considered data for 14 water quality parameters collected during 1990–2004 at 7 water quality monitoring sites. The results of fuzzy comprehensive assessment revealed that water quality in Yuqiao Reservoir Basin showed a downtrend from 1990 to 2001 with fluctuation, and a slowly upward trend after 2001. The major water quality belonged to Class III and IV. Besides, hierarchical cluster analysis divided 7 monitoring sites into two groups (Group A and B), and 12 months into three periods (low-flow (LF), normal-flow (NF), and high-flow (HF) period). Temp, pH, SS, T-har, DO, NO -N and TP were identified as significant variables affecting spatial variations, and Temp, pH and NO -N were identified as significant variables affecting temporal variations by discriminant analysis. Factor analysis identified four latent pollution sources for water quality variations: nutrient pollution, organic pollution, inorganic pollution, and natural pollution. Moreover, for Group A regions, pollution inputs mainly came from domestic wastewater and industrial sewage. For Group B regions, it is more likely that water pollution resulted from the combined effects of domestic wastewater, hospital wastewater, agriculture runoff, and fishpond discharge, as well as the incoming water from upstream.

关键词: Fuzzy comprehensive assessment     multivariate statistical analysis     water quality    

Factor analysis for the statistical modeling of earthquake-induced landslides

Jeng-Wen LIN, Meng-Hsun HSIEH, Yu-Jen LI

《结构与土木工程前沿(英文)》 2020年 第14卷 第1期   页码 123-126 doi: 10.1007/s11709-019-0582-y

摘要: Earthquake-induced landslides are difficult to assess and predict owing to the inherent unpredictability of earthquakes. In most existing studies, the landslide potential is statistically assessed by collecting and analyzing the data of historical landslide events and earthquake observation records. Unlike rainfall-induced landslides, earthquake-induced landslides cannot be predicted in advance using real-time monitoring systems, and the development of the models for these landslides should instead depend on early earthquake warnings and estimations. Hence, in this study, factor analysis was performed and the frequency distribution method was employed to investigate the potential risk of the landslides caused by earthquakes. Factors such as the slope gradient, lithology (geology), aspect, and elevation were selected and classified as influential factors to facilitate the construction of a landslide database for the area of study.

关键词: earthquake     factor analysis     slope landslides     statistical modeling    

Statistical analysis of residential building energy consumption in Tianjin

Jihong LING,Luhui ZHAO,Jincheng XING,Zhiqiang LU

《能源前沿(英文)》 2014年 第8卷 第4期   页码 513-520 doi: 10.1007/s11708-014-0327-5

摘要: To analyze the effect of energy conservation policies on energy consumption of residential buildings, the characteristics of energy consumption and indoor thermal comfort were investigated in detail in Tianjin, China, based on official statistical yearbook and field survey data. A comprehensive survey of 305 households indicates that the mean electricity consumption per household is 3215 kWh/a, in which annual cooling electricity consumption is 344 kWh/a, and the mean natural gas consumption for cooking is 103.2 m /a. Analysis of 3966 households data shows that space heating average intensity of residential buildings designed before 1996 is 133.7 kWh/(m ·a), that of buildings designed between 1996 and 2004 is 117.2 kWh/(m ·a), and that of buildings designed after 2004 is 105.0 kWh/(m ·a). Apparently, enhancing the performance of envelops is effective in reducing space heating intensity. Furthermore, the results of questionnaires show that 18% of the residents feel slightly warm and hot respectively, while 3% feel slightly cold in winter. Therefore, the electricity consumption in summer will rise for meeting indoor thermal comfort.

关键词: energy intensity     indoor thermal comfort     residential building     survey     statistical analysis     energy conversation    

Analysis on the distinguishing features of traditional Chinese therapeutics and related statistical issues

Jingqing Hu, Jie Qiao, Deying Kang, Baoyan Liu

《医学前沿(英文)》 2011年 第5卷 第2期   页码 203-207 doi: 10.1007/s11684-011-0138-6

摘要: Traditional Chinese medicine (TCM) is one of the rarely existing ancient traditional medicines that hold systematic theories as well as preventative and therapeutic methods for diseases in practice. From the 1950s, such research methods as mathematics, statistics, and data mining (DM) have been gradually introduced to TCM studies, making it more scientific. Meanwhile, the distinct features of TCM theories and diagnostic-model have constantly challenged the methodology of statistics. This paper introduces the following scientific features of traditional Chinese therapeutics: 1) its goal is to balance the functions and conditions of human body; 2) it emphasizes on holism and individualization; 3) it stresses the longitudinal regulation and evaluation mode, which is a circle of syndrome diagnosis, treatment and evaluation; 4) the interventions of TCM are abundant, compound and natural; and 5) humanistic thought is everywhere. Some statistical problems are raised based on these features. First, complex statistical methods that can analyze subjective indexes and latent variables, multidimensional and multistage data, non-equilibrium designed studies, and longitudinal data are required. Second, comprehensive evaluation on multiple-target mechanism has been brought in by combination treatment. Third, there is a need to analyze how humanity and related cultural factors may influence the effect of interventions. Thus, promoting implemented studies of statistics as well as carrying out the TCM scientific propositions have become the common expectations of both TCM and modern medicine.

关键词: traditional Chinese therapeutics     feature     statistic    

复杂耦合系统的统计能量分析及其应用

盛美萍

《中国工程科学》 2002年 第4卷 第6期   页码 77-84

摘要:

文章综合导纳分析法、经典统计能量分析方法和经典功率流理论的各自优点,提出适合复杂耦合系统的统计能量分析方法,为研究实际机械结构之间的振动传递规律、复杂机械系统的声辐射特性提供理论依据,为实际工程结构的振动隔离、噪声治理提供理论指导。文章首次提出统计能量分析参数必须统一定义,将影响实际机械结构相互之间能量传递的若干要素各自分离,并引入相应的参数分别开展研究。利用理论研究的成果,发展后的统计能量分析首次应用于水下航行器振动和噪声特性分析,预报了水下航行器的振动传递规律和辐射噪声级。理论分析与实验测试结果符合较好。文章指出了水下航行器噪声治理的方向。

关键词: 功率流     统计能量分析     导纳     耦合    

Development of mix design method based on statistical analysis of different factors for geopolymer concrete

Paramveer SINGH; Kanish KAPOOR

《结构与土木工程前沿(英文)》 2022年 第16卷 第10期   页码 1315-1335 doi: 10.1007/s11709-022-0853-x

摘要: The present study proposes the mix design method of Fly Ash (FA) based geopolymer concrete using Response Surface Methodology (RSM). In this method, different factors, including binder content, alkali/binder ratio, NS/NH ratio (sodium silicate/sodium hydroxide), NH molarity, and water/solids ratio were considered for the mix design of geopolymer concrete. The 2D contour plots were used to setup the mix design method to achieve the target compressive strength. The proposed mix design method of geopolymer concrete is divided into three categories based on curing regime, specifically one ambient curing (25 °C) and two heat curing (60 and 90 °C). The proposed mix design method of geopolymer concrete was validated through experimentation of M30, M50, and M70 concrete mixes at all curing regimes. The observed experimental compressive strength results validate the mix design method by more than 90% of their target strength. Furthermore, the current study concluded that the required compressive strength can be achieved by varying any factor in the mix design. In addition, the factor analysis revealed that the NS/NH ratio significantly affects the compressive strength of geopolymer concrete.

关键词: geopolymer concrete     mix design     fly ash     response surface methodology     compressive strength     stress−strain    

Statistical process control with intelligence using fuzzy ART neural networks

Min WANG, Tao ZAN, Renyuan FEI,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 149-156 doi: 10.1007/s11465-010-0008-y

摘要: With the automation development of manufacturing processes, artificial intelligence technology has been gradually employed to increase the automation and intelligence degree in quality control using statistical process control (SPC) method. In this paper, an SPC method based on a fuzzy adaptive resonance theory (ART) neural network is presented. The fuzzy ART neural network is applied to recognize the special disturbance of the manufacturing processes based on the classification on the histograms, which shows that the fuzzy ART neural network can adaptively learn the features of the histograms of the quality parameters in manufacturing processes. As a result, the special disturbance can be automatically detected when a feature of the special disturbance starts to appear in the histograms. At the same time, combined with spectrum analysis of the autoregressive model of quality parameters, the fuzzy ART neural network can also be utilized to adaptively detect the abnormal patterns in the control chart.

关键词: statistical process control (SPC)     fuzzy adaptive resonance theory (ART)     histogram     control chart     time series analysis    

Modeling of unconfined compressive strength of soil-RAP blend stabilized with Portland cement using multivariate

Ali Reza GHANIZADEH, Morteza RAHROVAN

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 787-799 doi: 10.1007/s11709-019-0516-8

摘要: The recycled layer in full-depth reclamation (FDR) method is a mixture of coarse aggregates and reclaimed asphalt pavement (RAP) which is stabilized by a stabilizer agent. For design and quality control of the final product in FDR method, the unconfined compressive strength of stabilized material should be known. This paper aims to develop a mathematical model for predicting the unconfined compressive strength (UCS) of soil-RAP blend stabilized with Portland cement based on multivariate adaptive regression spline (MARS). To this end, two different aggregate materials were mixed with different percentages of RAP and then stabilized by different percentages of Portland cement. For training and testing of MARS model, total of 64 experimental UCS data were employed. Predictors or independent variables in the developed model are percentage of RAP, percentage of cement, optimum moisture content, percent passing of #200 sieve, and curing time. The results demonstrate that MARS has a great ability for prediction of the UCS in case of soil-RAP blend stabilized with Portland cement ( is more than 0.97). Sensitivity analysis of the proposed model showed that the cement, optimum moisture content, and percent passing of #200 sieve are the most influential parameters on the UCS of FDR layer.

关键词: full-depth reclamation     soil-reclaimed asphalt pavement blend     Portland cement     unconfined compressive strength     multivariate adaptive regression spline    

Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters

DUAN Wei

《能源前沿(英文)》 2008年 第2卷 第1期   页码 107-115 doi: 10.1007/s11708-008-0018-1

摘要: Many stochastic parameters have an effect on the reliability of a steam turbine blade during practical operation. To improve the reliability of blade design, it is necessary to take these stochastic parameters into account. An equal cross-section blade is investigated and a finite element model is built parametrically. Geometrical parameters, material parameters and load parameters of the blade are considered as input random variables while the maximum deflection and maximum equivalent stress are output random variables. Analysis file of the blade is compiled by deterministic finite element method and applied to be loop file to create sample points. A quadratic polynomial with cross terms is chosen to regress these samples by step-forward regression method and employed as a surrogate of numerical solver to drastically reduce the number of solvers call. Then, Monte Carlo method is used to obtain the statistical characteristics and cumulative distribution function of the maximum deflection and maximum equivalent stress of the blade. Probability sensitivity analysis, which combines the slope of the gradient and the width of the scatter range of the random input variables, is applied to evaluate how much the output parameters are influenced by the random input parameters. The scatter plots of structural responses with respect to the random input variables are illustrated to analyze how to change the input random variables to improve the reliability of the blade. The results show that combination of the finite element method, the response surface method and Monte Carlo method is an ideal way for the reliability analysis and probability strength design of the blade.

关键词: Probability sensitivity     sensitivity analysis     number     cross-section     statistical    

Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange

ZHOU Xiaopeng, SU Xueli, SUN Yan

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 103-112 doi: 10.1007/s11705-007-0020-x

摘要: A study of nonlinear competitive adsorption equilibria of proteins is of fundamental importance in understanding the behavior of preparative chromatographic separation. This work describes the nonlinear binary protein adsorption equilibria on ion exchangers by the statistical thermodynamic (ST) model. The single-component and binary protein adsorption isotherms of bovine hemoglobin (Hb) and bovine serum albumin (BSA) on SP Sepharose FF were determined by batch adsorption experiments in 0.05 mol/L sodium acetate buffer at three pH values (4.5, 5.0 and 5.5) and three NaCl concentrations (0.05, 0.10 and 0.15 mol/L) at pH 5.0. The ST model was found to depict the effects of pH and ionic strength on the single-component equilibria well, with model parameters depending on the pH and ionic strength. Moreover, the ST model gave acceptable fitting to the binary adsorption data with the fitted single-component model parameters, leading to the estimation of the binary ST model parameter. The effects of pH and ionic strength on the model parameters are reasonably interpreted by the electrostatic and thermodynamic theories. Results demonstrate the availability of the ST model for describing nonlinear competitive protein adsorption equilibria in the presence of two proteins.

关键词: fundamental importance     single-component equilibria     acceptable fitting     hemoglobin     chromatographic separation    

三峡库区香溪河流域多变量生态水文风险的不确定性分析 Article

Yurui Fan,Guohe Huang,Yin Zhang,Yongping Li

《工程(英文)》 2018年 第4卷 第5期   页码 617-626 doi: 10.1016/j.eng.2018.06.006

摘要:

本研究基于copula函数开发了一种多变量生态水文风险评估框架,用于分析三峡库区香溪河流域极端生态水文事件的发生频率。通过马尔可夫链蒙特卡罗(MCMC)方法量化边缘分布及copula函数中参数的不确定性,并基于后验概率揭示联合重现期的内在不确定性,同时可进一步得到双变量及多变量风险的概率特征。研究结果显示所得概率模型的预测区间可很好地匹配观测值,尤其对洪水持续时间而言。同时,“AND”联合重现期的不确定性随着单个洪水变量重现期的增加而增加。此外,低设计流量及高服务年限可能导致高洪水风险且伴随大量不确定性。

关键词: 洪水风险     copula     多变量水文频率分析     概率分布     马尔科夫链蒙特卡罗    

Performance evaluation of circulating fluidized bed incineration of municipal solid waste by multivariate

Hua Tao, Pinjing He, Yi Zhang, Wenjie Sun

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0945-3

摘要: This first nationwide survey was conducted to evaluate the overall performance of the circulating fluidized bed (CFB) incineration of municipal solid waste (MSW) in 2014-2015 in China. Total 23 CFB incineration power plants were evaluated. The data for monthly average flue gas emission of particles, CO, NO , SO and HCl were collected over 12 consecutive months. The data were analyzed to assess the overall performance of CFB incineration by applying the Mahalanobis distance as a multivariate outlier detection method. Although the flue gas emission parameters had met the Chinese national emission standards, there were 11 total outliers (abnormal behavior) detected in 6 out of 23 CFB incineration power plants from the perspective of the MSW incineration performance. The results demonstrate that it is more important for a better performance of CFBs to reduce the frequencies of the MSW load changes, rather than the magnitudes of the MSW load changes, particularly reducing the frequencies in the range of 10% and more of the load changes, under the same and stable conditions. Furthermore, the overloading occurs more often than the underloading during the operation of the CFB incineration power plants in China. The frequent overloading is 0% to 30% of the designed capacity. To achieve the stable performance of CFBs in practice, an appropriately designed MSW storage capacity is suggested to build in a plant to buffer and reduce the frequency of the load changes.

关键词: Municipal solid waste     Incineration     Circulating fluidized bed     Load change     Multivariate outlier detection    

Image-based fall detection and classification of a user with a walking support system

Sajjad TAGHVAEI, Kazuhiro KOSUGE

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 427-441 doi: 10.1007/s11465-017-0465-7

摘要:

The classification of visual human action is important in the development of systems that interact with humans. This study investigates an image-based classification of the human state while using a walking support system to improve the safety and dependability of these systems. We categorize the possible human behavior while utilizing a walker robot into eight states (i.e., sitting, standing, walking, and five falling types), and propose two different methods, namely, normal distribution and hidden Markov models (HMMs), to detect and recognize these states. The visual feature for the state classification is the centroid position of the upper body, which is extracted from the user’s depth images. The first method shows that the centroid position follows a normal distribution while walking, which can be adopted to detect any non-walking state. The second method implements HMMs to detect and recognize these states. We then measure and compare the performance of both methods. The classification results are employed to control the motion of a passive-type walker (called “RT Walker”) by activating its brakes in non-walking states. Thus, the system can be used for sit/stand support and fall prevention. The experiments are performed with four subjects, including an experienced physiotherapist. Results show that the algorithm can be adapted to the new user’s motion pattern within 40 s, with a fall detection rate of 96.25% and state classification rate of 81.0%. The proposed method can be implemented to other abnormality detection/classification applications that employ depth image-sensing devices.

关键词: fall detection     walking support     hidden Markov model     multivariate analysis    

Experimental and statistical investigation of a new concrete-composite beam with encased polymer tube

Abdelmadjid SI SALEM,Souad AIT TALEB,Kamal AIT TAHAR

《结构与土木工程前沿(英文)》 2015年 第9卷 第2期   页码 154-162 doi: 10.1007/s11709-015-0296-8

摘要: A new concrete-composite beam with high mechanical performances to weight ratio is developed in this study. The proposed design technique consists to embed a cylindrical polymer tube wrapped by a GFRP Jacket in the mechanically ineffective concrete tensile zone. An experimental investigation is carried out on composite beams under bending loads until failure to evaluate the flexural capacity and the corresponding failure mechanisms. Based on the experimental results, statistical and preliminary reliability analyses using the FORM method are performed to assess the safety margin of the new beam. The confrontation between test and simulation results shows a satisfactory agreement, and represents a promising revelation regarding the improvement in terms of strength and ductility of such design compared to conventional reinforced concrete beams with traditional one.

关键词: design     GFRP-Jacket     polymer tube     test     reliability analysis    

标题 作者 时间 类型 操作

Assessment of temporal and spatial variations in water quality using multivariate statistical methods

Xue LI,Pengjing LI,Dong WANG,Yuqiu WANG

期刊论文

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

期刊论文

Factor analysis for the statistical modeling of earthquake-induced landslides

Jeng-Wen LIN, Meng-Hsun HSIEH, Yu-Jen LI

期刊论文

Statistical analysis of residential building energy consumption in Tianjin

Jihong LING,Luhui ZHAO,Jincheng XING,Zhiqiang LU

期刊论文

Analysis on the distinguishing features of traditional Chinese therapeutics and related statistical issues

Jingqing Hu, Jie Qiao, Deying Kang, Baoyan Liu

期刊论文

复杂耦合系统的统计能量分析及其应用

盛美萍

期刊论文

Development of mix design method based on statistical analysis of different factors for geopolymer concrete

Paramveer SINGH; Kanish KAPOOR

期刊论文

Statistical process control with intelligence using fuzzy ART neural networks

Min WANG, Tao ZAN, Renyuan FEI,

期刊论文

Modeling of unconfined compressive strength of soil-RAP blend stabilized with Portland cement using multivariate

Ali Reza GHANIZADEH, Morteza RAHROVAN

期刊论文

Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters

DUAN Wei

期刊论文

Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange

ZHOU Xiaopeng, SU Xueli, SUN Yan

期刊论文

三峡库区香溪河流域多变量生态水文风险的不确定性分析

Yurui Fan,Guohe Huang,Yin Zhang,Yongping Li

期刊论文

Performance evaluation of circulating fluidized bed incineration of municipal solid waste by multivariate

Hua Tao, Pinjing He, Yi Zhang, Wenjie Sun

期刊论文

Image-based fall detection and classification of a user with a walking support system

Sajjad TAGHVAEI, Kazuhiro KOSUGE

期刊论文

Experimental and statistical investigation of a new concrete-composite beam with encased polymer tube

Abdelmadjid SI SALEM,Souad AIT TALEB,Kamal AIT TAHAR

期刊论文